The present invention is related generally to a method and apparatus for manipulating small dielectric particles or other materials using optical gradient forces. In particular, the invention is related to a method and apparatus which uses focused laser light directed by a diffractive optical element, such as a hologram or diffraction grating, to create any one of a variety of selectable optical field patterns to assemble or direct particulate materials, or other affected materials, into a desired spatial pattern for any one of a myriad of uses.
It is known to construct optical tweezers using optical gradient forces from a single beam of light to manipulate the position of a small dielectric particle immersed in a fluid medium whose refractive index is smaller than that of the particle. The optical tweezer technique has been generalized to enable manipulation of reflecting, absorbing and low dielectric constant particles as well.
The current conventional systems therefore can manipulate a single particle by using a single beam of light to generate a single optical trap. To manipulate multiple particles with such systems, multiple beams of light must be employed. The difficulty of creating extended multiple-beam traps using conventional optical tweezer methodology inhibits their use in many potential commercial applications such as the fabrication and manipulation of nanocomposite materials including electronic, photonic and opto-electronic devices, chemical sensor arrays for use in chemical and biological assays, and holographic and computer storage matrices.
It is therefore an object of the invention to provide an improved method and system for establishing a plurality of optical traps.
It is another object of the invention to provide a novel method and system for using a single beam of light with diffractive optics for forming a configuration of light beams for establishing a plurality of optical traps.
It is an additional object of the invention to provide a novel method and apparatus for using holograms for generating an optical gradient field for controlling a plurality of particles or other optical media.
It is a further object of the invention to provide an improved method and system for establishing a plurality of optical traps for a variety of commercial applications relating to manipulation of small particles such as in photonic circuit manufacturing, nanocomposite material applications, fabrication of electronic components, opto-electronic devices, chemical and biological sensor arrays, assembly of holographic data storage matrices, facilitation of combinatorial chemistry applications, promotion of colloidal self-assembly, and the manipulation of biological materials.
It is still another object of the invention to provide an improved method and system for constructing a temporally and spatially varying configuration of optical gradient fields for commercial applications.
It is also an object of the invention to provide a novel method and system for using one or more laser beams in conjunction with one or more diffractive optical elements for constructing a selectable time varying and/or particular spatial array of optical traps for manipulating a dielectric material.
It is yet a further object of the invention to provide an improved method and system using a single input laser beam, a diffractive optical element, and a diverging and/or converging lens to form a static or dynamic optical trap.
It is still an additional object of the invention to provide a novel method and system for constructing an optical trap array which is directly observable by a user.
It is also a further object of the invention to provide an improved method and system employing a laser beam input to a diffractive optical element with a beam scanning system enabling scanning of an array of optical traps for various commercial applications.
It is in addition another object of the invention to provide a novel method and apparatus for constructing an optical trap configuration using a laser beam, a diffractive optical element and a diverging or converging optical system to form the trap configuration at a selectable location relative to an objective lens focal plane.
It is still another object of the invention to provide an improved method and apparatus for using a laser beam and an obliquely positioned diffractive optical element to filter out any undiffracted beam for efficient utilization of only a diffracted optical beam in constructing an optical trap arrangement.
It is yet another object of the invention to provide a novel method and apparatus for using a laser beam input to a diffractive optical element to generate at least a two-dimensional arrangement of optical traps out of the focal plane of an objective lens.
It is also yet another object of the invention to provide an improved method and system for employing a light beam and diffractive optics in conjunction with a plurality of telescope lenses to scan an optical trap array.
It is yet an additional object of the invention to provide a novel method and system for establishing an array of optical traps using a single light beam input to a diffractive optical element and an optical system for controllably scanning the optical trap array such that small amplitude oscillatory displacements are applied to dynamically stiffen the optical traps.
It is another object of the invention to provide a novel method for creating multiple independently steered optical traps using a time-dependent addressable phase-shifting medium (such as a liquid crystal phase shifting array) as a diffractive optical element.
It is a further object of the invention to provide a novel method for creating time-dependent optical gradient fields for the segregation of microscopic particles.
It is yet another object of the invention to provide a novel method for manipulating a plurality of biological objects including the crystallization of proteins.